Check if Race is Black
Examples
is_black("WHITE")
#> [1] FALSE
is_black(c("AFRICAN AMERICAN", "BLACK"))
#> [1] TRUE TRUE
is_black(2)
#> Numeric input detected - assuming 1 = White, 2 = Black, 3 = Asian, 4 = American Native, 5 = Pacific Islander, 6 = Other, -999 = Missing.
#> [1] TRUE
